The No. 2 U.S. mobile operator said Friday that it would make the shift Oct 25. It said it was streamlining its offerings because the data-share plans are its most popular.

AT&T added that existing customers could keep their current plans, even when they upgrade to a new device, unlike its biggest rival Verizon Wireless. Both companies introduced shared-data service plans in 2012.

Investors say these plans could help operators such as AT&T and Verizon retain customers at a time when competition is ramping up in the U.S. wireless industry.

In particular, AT&T is facing increasingly aggressive competition from No. 4 U.S. operator T-Mobile US Inc., which compares itself directly to AT&T in its marketing.

The idea is that customers subscribing to shared-data plans might be less inclined to switch to another carrier if their cellular service for several devices, including smartphones and tablet computers, is attached a single plan.

Carriers also see the plans as a way to encourage subscribers to add more devices and increase how much they spend on cellphone service.